Commit 5568355e authored by Liu Xiaodong's avatar Liu Xiaodong Committed by Tomasz Zawadzki
Browse files

vhost-blk: apply interrupt 



If interrupt mode is set, related poller functions will be
registered to interrupt handler instead of poller.
interrupt_tgt can work as vhost-blk target to support VM.

Change-Id: I3a15f9a63532f44fe0d2f0cb69b0efdd72431d10
Signed-off-by: default avatarLiu Xiaodong <xiaodong.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4277


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent 7229b8e1

examples/interrupt_tgt/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -55,6 +55,9 @@ SPDK_LIB_LIST += bdev_malloc bdev_passthru bdev_error bdev_gpt bdev_split bdev_r 
SPDK_LIB_LIST += bdev_lvol lvol blob_bdev blob

# blobfs libraries

SPDK_LIB_LIST += blobfs blobfs_bdev

# vhost blk related libraries.

SPDK_LIB_LIST += vhost event_vhost

SPDK_LIB_LIST += scsi event_scsi # vhost-scsi is not supported, just because vhost lib requires scsi related libs



ifeq ($(SPDK_ROOT_DIR)/lib/env_dpdk,$(CONFIG_ENV))

SPDK_LIB_LIST += env_dpdk_rpc

examples/interrupt_tgt/interrupt_tgt.c

+6 −1
Original line number Diff line number Diff line
@@ -34,17 +34,22 @@ 
#include "spdk/stdinc.h"

#include "spdk/conf.h"

#include "spdk/event.h"

#include "spdk/vhost.h"



static void

interrupt_tgt_usage(void)

{

	printf(" -E                        Set interrupt mode\n");

	printf(" -S <path>                 directory where to create vhost sockets (default: pwd)\n");

}



static int

interrupt_tgt_parse_arg(int ch, char *arg)

{

	switch (ch) {

	case 'S':

		spdk_vhost_set_socket_path(arg);

		break;

	case 'E':

		spdk_interrupt_mode_enable();

		break;
@@ -68,7 +73,7 @@ main(int argc, char *argv[]) 
	spdk_app_opts_init(&opts);

	opts.name = "interrupt_tgt";



	if ((rc = spdk_app_parse_args(argc, argv, &opts, "E", NULL,

	if ((rc = spdk_app_parse_args(argc, argv, &opts, "S:E", NULL,

				      interrupt_tgt_parse_arg, interrupt_tgt_usage)) !=

	    SPDK_APP_PARSE_ARGS_SUCCESS) {

		exit(rc);

lib/vhost/vhost.c

+52 −4
Original line number Diff line number Diff line
@@ -199,6 +199,38 @@ vhost_vq_avail_ring_get(struct spdk_vhost_virtqueue *virtqueue, uint16_t *reqs, 
	}



	count = spdk_min(count, reqs_len);

	if (virtqueue->vsession && virtqueue->vsession->interrupt_mode) {

		/* if completed IO number is larger than SPDK_AIO_QUEUE_DEPTH,

		 * io_getevent should be called again to ensure all completed IO are processed.

		 */

		int rc;

		uint64_t num_events;



		rc = read(vring->kickfd, &num_events, sizeof(num_events));

		if (rc < 0) {

			SPDK_ERRLOG("failed to acknowledge kickfd: %s.\n", spdk_strerror(errno));

			return -errno;

		}



		if ((uint16_t)(avail_idx - last_idx) != num_events) {

			SPDK_DEBUGLOG(vhost_ring,

				      "virtqueue gets %d reqs, but kickfd shows %lu reqs\n",

				      avail_idx - last_idx, num_events);

		}



		if (num_events > count) {

			SPDK_DEBUGLOG(vhost_ring,

				      "virtqueue kickfd shows %lu reqs, take %d, send notice for other reqs\n",

				      num_events, reqs_len);

			num_events -= count;

			rc = write(vring->kickfd, &num_events, sizeof(num_events));

			if (rc < 0) {

				SPDK_ERRLOG("failed to kick vring: %s.\n", spdk_strerror(errno));

				return -errno;

			}

		}

	}



	virtqueue->last_avail_idx += count;

	for (i = 0; i < count; i++) {

		reqs[i] = vring->avail->ring[(last_idx + i) & size_mask];
@@ -500,6 +532,14 @@ vhost_vq_used_ring_enqueue(struct spdk_vhost_session *vsession, 
	rte_vhost_clr_inflight_desc_split(vsession->vid, vq_idx, virtqueue->last_used_idx, id);



	virtqueue->used_req_cnt++;



	if (vsession->interrupt_mode) {

		if (virtqueue->vring.desc == NULL || vhost_vq_event_is_suppressed(virtqueue)) {

			return;

		}



		vhost_vq_used_signal(vsession, virtqueue);

	}

}



void
@@ -1194,6 +1234,10 @@ vhost_start_device_cb(int vid) 
		goto out;

	}



	if (spdk_interrupt_mode_is_enabled()) {

		vsession->interrupt_mode = true;

	}



	vdev = vsession->vdev;

	if (vsession->started) {

		/* already started, nothing to do */
@@ -1242,12 +1286,16 @@ vhost_start_device_cb(int vid) 
			q->packed.used_phase = q->last_used_idx >> 15;

			q->last_used_idx = q->last_used_idx & 0x7FFF;



			if (!vsession->interrupt_mode) {

				/* Disable I/O submission notifications, we'll be polling. */

				q->vring.device_event->flags = VRING_PACKED_EVENT_FLAG_DISABLE;

			}

		} else {

			if (!vsession->interrupt_mode) {

				/* Disable I/O submission notifications, we'll be polling. */

				q->vring.used->flags = VRING_USED_F_NO_NOTIFY;

			}

		}



		q->packed.packed_ring = packed_ring;

		vsession->max_queues = i + 1;

lib/vhost/vhost_blk.c

+97 −4
Original line number Diff line number Diff line
@@ -690,6 +690,14 @@ _vdev_vq_worker(struct spdk_vhost_virtqueue *vq) 


}



static int

vdev_vq_worker(void *arg)

{

	struct spdk_vhost_virtqueue *vq = arg;



	return _vdev_vq_worker(vq);

}



static int

vdev_worker(void *arg)

{
@@ -788,6 +796,14 @@ _no_bdev_vdev_vq_worker(struct spdk_vhost_virtqueue *vq) 
	return SPDK_POLLER_BUSY;

}



static int

no_bdev_vdev_vq_worker(void *arg)

{

	struct spdk_vhost_virtqueue *vq = arg;



	return _no_bdev_vdev_vq_worker(vq);

}



static int

no_bdev_vdev_worker(void *arg)

{
@@ -802,6 +818,55 @@ no_bdev_vdev_worker(void *arg) 
	return SPDK_POLLER_BUSY;

}



static void

vhost_blk_session_unregister_interrupts(struct spdk_vhost_blk_session *bvsession)

{

	struct spdk_vhost_session *vsession = &bvsession->vsession;

	struct spdk_vhost_virtqueue *vq;

	int i;



	SPDK_DEBUGLOG(vhost_blk, "unregister virtqueues interrupt\n");

	for (i = 0; i < vsession->max_queues; i++) {

		vq = &vsession->virtqueue[i];

		if (vq->intr == NULL) {

			break;

		}



		SPDK_DEBUGLOG(vhost_blk, "unregister vq[%d]'s kickfd is %d\n",

			      i, vq->vring.kickfd);

		spdk_interrupt_unregister(&vq->intr);

	}

}



static int

vhost_blk_session_register_interrupts(struct spdk_vhost_blk_session *bvsession,

				      spdk_interrupt_fn fn)

{

	struct spdk_vhost_session *vsession = &bvsession->vsession;

	struct spdk_vhost_virtqueue *vq = NULL;

	int i;



	SPDK_DEBUGLOG(vhost_blk, "Register virtqueues interrupt\n");

	for (i = 0; i < vsession->max_queues; i++) {

		vq = &vsession->virtqueue[i];

		SPDK_DEBUGLOG(vhost_blk, "Register vq[%d]'s kickfd is %d\n",

			      i, vq->vring.kickfd);



		vq->intr = SPDK_INTERRUPT_REGISTER(vq->vring.kickfd, fn, vq);

		if (vq->intr == NULL) {

			SPDK_ERRLOG("Fail to register req notifier handler.\n");

			goto err;

		}

	}



	return 0;



err:

	vhost_blk_session_unregister_interrupts(bvsession);



	return -1;

}



static struct spdk_vhost_blk_dev *

to_blk_dev(struct spdk_vhost_dev *vdev)

{
@@ -863,6 +928,7 @@ vhost_session_bdev_remove_cb(struct spdk_vhost_dev *vdev, 
			     void *ctx)

{

	struct spdk_vhost_blk_session *bvsession;

	int rc;



	bvsession = (struct spdk_vhost_blk_session *)vsession;

	if (bvsession->requestq_poller) {
@@ -870,6 +936,16 @@ vhost_session_bdev_remove_cb(struct spdk_vhost_dev *vdev, 
		bvsession->requestq_poller = SPDK_POLLER_REGISTER(no_bdev_vdev_worker, bvsession, 0);

	}



	if (vsession->virtqueue[0].intr) {

		vhost_blk_session_unregister_interrupts(bvsession);

		rc = vhost_blk_session_register_interrupts(bvsession, no_bdev_vdev_vq_worker);

		if (rc) {

			SPDK_ERRLOG("%s: Interrupt register failed\n", vsession->name);

			return -1;

		}



	}



	return 0;

}
@@ -1013,10 +1089,22 @@ vhost_blk_start_cb(struct spdk_vhost_dev *vdev, 
		}

	}



	if (spdk_interrupt_mode_is_enabled()) {

		rc = vhost_blk_session_register_interrupts(bvsession,

				bvdev->bdev ? vdev_vq_worker : no_bdev_vdev_vq_worker);

		if (rc) {

			SPDK_ERRLOG("%s: Interrupt register failed\n", vsession->name);

			goto out;

		}

		SPDK_INFOLOG(vhost, "%s: started interrupt source on lcore %d\n",

			     vsession->name, spdk_env_get_current_core());

	} else {

		bvsession->requestq_poller = SPDK_POLLER_REGISTER(bvdev->bdev ? vdev_worker : no_bdev_vdev_worker,

					     bvsession, 0);

		SPDK_INFOLOG(vhost, "%s: started poller on lcore %d\n",

			     vsession->name, spdk_env_get_current_core());

	}



out:

	vhost_session_start_done(vsession, rc);

	return rc;
@@ -1072,6 +1160,11 @@ vhost_blk_stop_cb(struct spdk_vhost_dev *vdev, 
	struct spdk_vhost_blk_session *bvsession = to_blk_session(vsession);



	spdk_poller_unregister(&bvsession->requestq_poller);



	if (vsession->virtqueue[0].intr) {

		vhost_blk_session_unregister_interrupts(bvsession);

	}



	bvsession->stop_poller = SPDK_POLLER_REGISTER(destroy_session_poller_cb,

				 bvsession, 1000);

	return 0;

lib/vhost/vhost_internal.h

+3 −0
Original line number Diff line number Diff line
@@ -124,6 +124,8 @@ struct spdk_vhost_virtqueue { 
	uint32_t vring_idx;



	struct spdk_vhost_session *vsession;



	struct spdk_interrupt *intr;

} __attribute((aligned(SPDK_CACHE_LINE_SIZE)));



struct spdk_vhost_session {
@@ -141,6 +143,7 @@ struct spdk_vhost_session { 
	bool started;

	bool needs_restart;

	bool forced_polling;

	bool interrupt_mode;



	struct rte_vhost_memory *mem;